12a, Hertford Road, Tewin, Welwyn, AL6 0JY
About 12a
12a is a detached house in Tewin, Welwyn, Welwyn (AL6 0JY). It has a recorded floor area of 168 m² (around 1808 sq ft). The latest certificate (February 2019) returns a high B (score 85), putting the home a stone's throw from an A rating. The recommended improvements would push it to A (score 92).
One planning record on file: an annexe approved in 2007. Past consents include an annexe, meaningful when judging how the property has evolved. Its energy rating outperforms most of the postcode (better than 75% of similar EPCs). Today's modelled estimate of £1,037,000 is 18.5% above the 2019 sale price. On a £-per-square-foot basis, the last sale (£484/sq ft) was about 18.5% above the typical sold price in the postcode. Sold March 2019 for £875,000.
Know exactly what you're buying at 12a
Before you offer, see what the listing won't tell you, the true value, the red flags and the full history.
Already flagged here
Valuation
against the asking price
Risks
planning & flood
Sold prices
similar homes nearby
Trends
the local market
Energy performance
EPC Rating
Planning history
- Apr 2007AnnexHeritageIn report
Alterations and improvements to existing granny annexe including removal of internal partition, relocation of the kitchen and creation of w.c. on ground floor. Conversion of adjacent stable outbuilding to sitting room with enlargement of window.
- Documents
- 4 docs on file
- Reference
- 3/07/0506/LB
We flagged 1 thing worth checking at 12a
Independent checks surfaced things a buyer would want to understand before offering. The report explains each one in full, with the underlying data and what to ask.
- Larger development activity nearby
30-day money-back guarantee
Sales history & valuation
12a valuation sits well clear of the typical sold price in this postcode.
£1,037,000
Modelled from EPC, postcode comparables.
£875,000
Recorded with HM Land Registry.
Sales timeline
15 March 2019Most recent
£875,000
Median price across the last 5 sales in AL6 0JY: £755,000 (2021–2015).
Nearby sales in AL6 0JY
4 Hertford Road, Tewin, Welwyn, AL6 0JY
Sold Jun 2021
£516,00012b, Hertford Road, Tewin, Welwyn, AL6 0JY
Sold Feb 2019
£895,00020 Hertford Road, Tewin, Welwyn, AL6 0JY
Sold May 2016
£750,00022a, Hertford Road, Tewin, Welwyn, AL6 0JY
Sold Jun 2015
£755,0002a, Hertford Road, Tewin, Welwyn, AL6 0JY
Sold May 2015
£765,000
Everything we know about 12a, in one report
What it's really worth, what could be wrong, and the planning, sales and area data in full.
What we flagged
- Larger development activity nearby

Versus other Hertford Road homes
12a outperforms the street on epc rating by a wide margin.
Price per m²
£5,208
Street avg £4,975
Floor Area
168 m²
Street avg 155 m²
CO₂ Emissions
2.3 t/year
Street avg 6.0 t/year
Years Held
7 years
Street avg 12 years
Similar properties nearby
The neighbourhood at a glance
Crime
2/mo
Steady year-on-year across the wider district.
Nearest stop
0.2 km
Rose and Crown PH — bus stop.
Closest school
0.1 km
Tewin Cowper Church of England Voluntary Aided Primary School. 8 schools nearby.
Go deeper on the local area
The full report breaks down crime, transport links, schools and air quality in depth.